Epidural Catheter With or Without Adductor Canal Nerve Block for Postoperative Analgesia Following Total Knee Arthroplasty

ACNB catheter will be placed by anesthesia residents under the supervision of board-certified anesthesiologists familiar with regional anesthesia techniques, who are part of the anesthesia pain service. They will be performed at the bedside, aseptically, with the patient's vital signs monitored throughout the procedure. 1% lidocaine will be infiltrated in the skin and subcutaneous tissues overlying the adductor canal as visualized on ultrasound. Via a 17 gauge touhy needle a closed tip non-stimulating, epidural catheter will be placed after 1% lidocaine is used to hydrodissect the space lateral to the superficial femoral artery within the adductor canal. The catheter will be secured to the skin. All catheters will be connected to infusion pumps with opaque plastic bags covering the pumps. The functional ACNB pumps will run 8cc/h.

Patients randomized to the sham catheter will have a chlorhexidine prep of the skin and ultrasound examination of the adductor canal on postoperative day #1. To minimize patient risk, a wooden applicator will be used to apply 10 seconds of pressure to the leg followed by catheter securing to the skin with the same tegaderm and paper tape dressing used on functional catheters. All catheters will be connected to infusion pumps with opaque plastic bags covering the pumps. The sham catheter pumps will not be turned on.

In the functioning continuous adductor canal block, 0.125% bupivacaine will be infused at a rate of 8cc/hr.